Stardate: 5431.4, 4351.5, 5431.6, 5432.3--A woman from a strange alien ship transports to the Enterprise.She stuns everyone on the bridge with a device on her forearm and takes an interest in Spock.

However, when Kirk and McCoy wake up, they discover that that the woman has taken Spock's brain! They rig up something to keep his body alive but even a Vulcan can only survive a limited time without a brain, so they must track down the woman's ship and recover the missing organ.

original airdate--September 20, 1968

network: NBC

music:"Theme from Star Trek" "Where No Man Has Gone Before" by Alexander Courage

Alien Races: Sigma Draconians

Trivia--The fourth, fifth, and sixth planets of the Sigma Draconis star system are Class-M and support humanoid societies at various levels of development.

Space: the final frontier. These are the voyages of the starship Enterprise. Its five-year mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no man has gone before.